Spencer in NH
Stainless
- Joined
- Jan 22, 2007
- Location
- Southern New Hampshire
Recently, I purchased a used Suburban Tool squaring chuck, the MC-66-FP-S1, from someone on eBay. It looked decent, and was less than half the price of a new one. I figured I can tweak it in if it needed it.
Inspection of the chuck indicated that someone did some light milling on it, cutting a few thou into the chuck surface. So, I would be grinding the chuck working surface in any event. The chuck also spun on the surface plate indicating that the base was convex. I measured a worst case at a corner of eight tenths low. In for a penny, in for a pound, I started formulating a plan to grind.
This was also an educational experience for me, as I am a grinding newbie. Also, the cost of sending it in to Suburban Tool was one-half the cost of new. So, I decided that was better spent as time getting experience.
The below pictures will tell the story.
Inspection of the top (magnetic) surface of the chuck showed that it was concave, and low in the center. The corners looked like they still had evidence of the grinding marks from the factory. Putting it face down on the surface plate and indicating it with a tenths indicator showed zero rock face down. So, I decided this would be my primary reference. It took a bit more than a thou to clean up the bottom. Then I flipped it over and ground the top. (Sorry I don't have a good "before" picture of the top.) I decided not to chase the last of the blemish on the top as it would not really affect use, and I wanted to minimize material removal.
I had recently bought a B&S 6-inch cylindrical square as a reference for this project (and others... thanks, Mike), and that was my reference for square. Grinding the sides square to the face was interesting. I learned how to shim and walk two opposing sides into square with the reference surface. One picture shows an interesting setup where I used three pins to support the chuck and 1-2-3 blocks to block it in. The single pin supporting the bottom edge was chosen to shim-to-square. This worked very well.
I am not quite done, but at this point I am chasing tenths. I am very pleased with how things are working, and I am finally getting some confidence in driving my Harig 612.
My thanks to Don Bailey of Suburban Tool (SubTool.com), and to Phil Kerner of TheToolAndDieGuy.com for their excellent instructional videos.
Watching the hands of a grinding master is worth reading at least a dozen books.
Inspection of the chuck indicated that someone did some light milling on it, cutting a few thou into the chuck surface. So, I would be grinding the chuck working surface in any event. The chuck also spun on the surface plate indicating that the base was convex. I measured a worst case at a corner of eight tenths low. In for a penny, in for a pound, I started formulating a plan to grind.
This was also an educational experience for me, as I am a grinding newbie. Also, the cost of sending it in to Suburban Tool was one-half the cost of new. So, I decided that was better spent as time getting experience.
The below pictures will tell the story.
Inspection of the top (magnetic) surface of the chuck showed that it was concave, and low in the center. The corners looked like they still had evidence of the grinding marks from the factory. Putting it face down on the surface plate and indicating it with a tenths indicator showed zero rock face down. So, I decided this would be my primary reference. It took a bit more than a thou to clean up the bottom. Then I flipped it over and ground the top. (Sorry I don't have a good "before" picture of the top.) I decided not to chase the last of the blemish on the top as it would not really affect use, and I wanted to minimize material removal.
I had recently bought a B&S 6-inch cylindrical square as a reference for this project (and others... thanks, Mike), and that was my reference for square. Grinding the sides square to the face was interesting. I learned how to shim and walk two opposing sides into square with the reference surface. One picture shows an interesting setup where I used three pins to support the chuck and 1-2-3 blocks to block it in. The single pin supporting the bottom edge was chosen to shim-to-square. This worked very well.
I am not quite done, but at this point I am chasing tenths. I am very pleased with how things are working, and I am finally getting some confidence in driving my Harig 612.
My thanks to Don Bailey of Suburban Tool (SubTool.com), and to Phil Kerner of TheToolAndDieGuy.com for their excellent instructional videos.
Watching the hands of a grinding master is worth reading at least a dozen books.
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